This invention relates to LED lighting circuits. More specifically this invention relates to a circuit for providing improved operation of an LED lighting device.
LED lighting is an energy efficient lighting source is becoming more and more popular world-wide. Several ways exist regarding how to successfully operate and dim LED devices. In particular, typically line voltage is AC or alternating current voltage where the voltage and current are represented by a sine wave. One circuit that can be used to operate and dim LED utilizes a rectifier and AC to DC converter in association with a PWM device to provide diming.
In an alternative embodiment applicant eliminated the AC to DC converter and need for a PWM device through conditioning the AC current directly provided to the LEDs. This is shown in applicant's U.S. Pat. No. 8,373,363 that is incorporated in full herein. While effective at operating and dimming, problems remain. During analog operation there are times during operation where current exists at zero cross for extended periods of time. For certain operations light is desired during this period. As one example, some flicker indexes put out by specification makers focus, not just on frequency of the AC sine wave, but also on the drop in current from peak to the valley of the sine wave.
Similarly, some flicker indexes require that AC LED operate at above 200 Hz as an acceptable frequency, regardless of waveform or shape, peak to valley measurements or the like. Thus a need exists in analog circuits to increase frequency to address flicker standards within the industry.
Therefore, a principle object of the present invention is to improve functionality of an AC analog circuit.